Fast pyrolysis is a thermochemical process that breaks down organic material into smaller vaporous molecules (both condensable and non-condensable) and solid charred material via rapid heating in the absence of oxygen. When the fast pyrolysis process is applied to a biomass feedstock, fast pyrolysis produces greater quantities of condensable gases (used to generate bio-oils) than more conventional gasification methods, which produce primarily non-condensable gases (i.e. syngas).
Fast pyrolysis of biomass is typically accomplished by exposing a biomass feedstock to temperatures between 450 and 550° C. in the absence of oxygen. During the fast pyrolysis process, the feedstock is transformed into combustible gases and biochar in an inert gas atmosphere that does not support combustion. The condensable gases are then cooled and recovered as a liquid (bio-oil). The heating rate is generally on the order of 1000° C./s. This is typically done in a fluidized bed or entrained gas reactor that is able to achieve the high heat transfer rates necessary for fast pyrolysis.
The bio-oils produced through the fast pyrolysis process are typically acidic and exhibit increased viscosity and average molecular weight with age. Considerable current research is devoted to investigating use of catalysts to deoxygenate bio-oils to increase bio-oil stability so that the bio-oil would be a suitable refinery feedstock for production of renewable transportation fuels. However, duplicating the conditions for fast pyrolysis on a scale suitable for screening catalysts is problematic. Commercially available micropyrolysis reactors can accomplish this duplication at the milligram level, but these reactors do not produce quantities of bio-oil necessary for comprehensive analysis and aging studies. Other attempts to scale down fast pyrolysis have used external feedstock heating processes, however, these process do not heat quickly enough.
The need exists for a pyrolysis method and apparatus that generates sufficient quantities of bio-oil for at least experimental investigation and analysis. The “catalytic cracking pipe” system of the current invention embodies the solution to many of the prior art process problems and generates high quality bio-oil in at least sufficient quantities for further research.